brothel.

Short for brothel-house (“house of prostitution”), from brothel (“a wretch; scoundrel; lecher; harlot; prostitute”) + house, influenced by bordel. For more on brothel (“a wretch”), see below.

From Middle English brothel, brodel, brodelle, brethel (“a wretch, a depraved man or woman”) (compare also Middle English bretheling (“a wretch”)), apparently from an unrecorded Old English *brēoþel (“degenerative, corruptive”), related to Old English ābrēoþan (“to unsettle, degrade, ruin, frustrate, degenerate, deteriorate, fall away”); Old English ābroþen (“degenerate, base, trifling”); both ultimately from Proto-Germanic *breuþaną (“to fall apart; crumble”). The expected modern English form would be *broddle (see fiddle); the failure of the change from /ðl/ to /dl/ may be because of the intervening schwa in the word's uninflected forms, influence from the verb, or most likely, a dialectal development (compare stathel besides staddle).